Fine gold alloy wire for bonding of a semi-conductor device

Abstract

A fine gold alloy wire of high tensile strength for bonding semiconductor elements is disclosed. The wire consists essentially of 0.0003 to 0.010 wt % of at least one rare earth element selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu,Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc and Y, the balance being Au and incidental impurities. The wire does not present a deformed loop and has greater bond strength if it contains 0.0003 to 0.010 wt % of at least one rare earth element of the Cerium Group selected from the group consisting of La, Ce, Pr, Nd and Sm and 0.0001 to 0.0060 wt % of at least one element selected from among Ge, Be and Ca.

What is claimed is: 
     
       1. A fine gold alloy wire for use in the bonding of semiconductor elements characterized by having high tensile strength and consisting essentially from 0.0003 to less than 0.0010 wt% of at least one rare earth element selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc and Y, with the balance being Au and incidental impurities. 
     
     
       2. The fine gold wire of claim 1 wherein said rare earth element is selected from the group consisting of La, Ce, Pr, Nd, and Sm. 
     
     
       3. A fine gold alloy wire for use in the bonding of semiconductor elements characterized by having high tensile strength and consisting essentially of 0.0003 to less than 0.0010 wt% of at least one rare earth element selected from the group consisting of La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Lu, Sc and Y, and 0.0001 to 0.0060 wt% of of at least one element selected from the group consisting of Ge, Be and Ca, with the balance being Au and incidental impurities. 
     
     
       4. The fine gold wire of claim 3 wherein said rare earth element is selected from the group consisting of La, Ce, Pr, Nd, and Sm.